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Enabling Global Multimedia Distributed Services based on Hierarchical DHT Overlay Networks. Isaias Martinez-Yelmo , Alex Bikfalvi, Carmen Guerrero, Ruben Cuevas, Andreas Mauthe imyelmo@it.uc3m.es. Overview. Introduction P2PSIP Hierarchical-ID Service Mapping Routing on Hierarchical DHT
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Enabling Global Multimedia Distributed Services based on Hierarchical DHT Overlay Networks Isaias Martinez-Yelmo, Alex Bikfalvi, Carmen Guerrero, Ruben Cuevas, Andreas Mauthe imyelmo@it.uc3m.es
Overview • Introduction • P2PSIP • Hierarchical-ID • Service Mapping • Routing on Hierarchical DHT • Analytical Performance • Validation via Simulation • Conclusions • Future Work
Introduction • Objective • Enabling Global Multimedia Distributed Services based on Hierarchical DHT Overlay Networks • P2PSIP is an excellent candidate for Multimedia Distributed Services • But, Global connectivity between different Distributed Services has yet not been considered • Our proposal tries to overcome this missing feature
P2PSIP – What is P2PSIP? • P2PSIP is an IETF Working Group • Objectives • To provide a protocol that allows Distributed Multimedia Services • The motivation is to provide Skype-like services based on an open standard • User friendly • NAT Traversal based on ICE protocol • Functionality on Multimedia Services • Distributed replacement of SIP entities • Proxys • Registrars
P2PSIP – Features • RELOAD is the P2PSIP protocol • It is payload can support any type of p2p network • Specially DHT networks (Chord, Kademlia, …) • An Overlay-ID exist to differentiate the difference instances • It supports all the needed primitives: Join, Fetch, … • It can also support NAT traversal based on ICE • What is not being defined? • The type of information stored on the p2p network • How the information is stored on the p2p network • It depends on the application • Resource/Service Mapping
P2PSIP - Limitation Domain.a Domain.c Interconnection Overlay Domain.d Domain.b
Hierarchical-ID • Prefix-ID • It is only used in the Interconnection Overlay • Routing at Super-peer level • Suffix-ID • It is only used internally within each P2PSIP domain • Routing at Peer level
Service Mapping • Is not defined by P2PSIP WG • Depends on the application • Should be based on URI’s • A simple example • URI: resource_or_service@example.com • Prefix-ID = hash(example.com) • Suffix-ID= hash(resource_or_service@example.com) • More complex mappings could be used
Routing on Hierarchical DHT’s • If different hashes or mapping functions are used in each overlay • Interconnection • Own domain • A direct response cannot be used
Inter-cluster Intra-cluster P2PSIP domain Interconnection Overlay Analytical Performance • General Formulation for Routing Performance: • After simplifications: • In Kademlia:
Validation via Simulation • Simulator: PeerFactSim.Kom based on Java • Simple Network Model • Hierarchical Kademlia implementation • It is based on its Kademlia implementation • K=20, Alpha=1, B=2b=2 • Domains: 5, 10, 20 • Peers: 10-1000 • Up to 10,000 peers • 64-bit Intel Architecture with 8GB RAM (2 weeks) • 95% Confidence Intervals have been calculated • The error is smaller than a 5%
Routing Performance for intra--domain for Node and Value lookups
Conclusions • We purpose a method for interconnecting P2PSIP domains • This mechanism enables Global Multimedia Distributed Services based on Hierarchical DHT Overlay Networks • The main points are: • The Hierarchical-ID • The Service and Resources Mapping • The signalling flow • Based on the P2PSIP protocol (RELOAD) • Peers do not increase its Routing State • Scalable Solution • Only Super-Peers are highly loaded • Bandwidth • The Routing Performance is not affected by this architecture
Future Work • More detailed simulations • More domains • Churn Rate • Modifications on the scenario • VoIP + Social/Community Networks • More VoIP calls based on P2PSIP being done inside the Social/Community Network • Global Routing Performance changes • Super-peer management
Questions? Isaias Martinez-Yelmo, Alex Bikfalvi, Carmen Guerrero, Ruben Cuevas, Andreas Mauthe imyelmo@it.uc3m.es Enabling Global Multimedia Distributed Services Based on Hierarchical DHT Overlay Networks